Water filtration devices for local communities, implemented with the aim of supplying water suitable for human consumption, traditionally use series of ultrafiltration modules arranged side by side. An ultrafiltration technique is considered here that uses hollow fibers supplied with water under a pressure of a few bars, such that the filtration sought is performed by the waters passage from the exterior of the fiber towards the interior through the porous wall forming its membrane. These modules, of cylindrical shape overall, comprise substantially cylindrical bundles of several hundreds of such hollow fibers.
In a particular mode of implementation, these modules are supplied with untreated water via their upper extremity. The water purified after passing through the wall of the membranes is also collected at the upper extremity. The treatment sludge is evacuated by a lower drain. It is understood that, depending on the maximum quantity of water that must be treated per unit of time, larger or smaller series of modules are installed between the horizontal pipes for water inlet and outlet and for sludge drainage.
When one of the hollow fibers breaks, it lets untreated water pass through in the flow of water supposed to be drinkable on output. For obvious public health reasons such a situation cannot be maintained for long. Also, various mechanisms for detecting and closing damaged fibers have been put in place over time.
Furthermore, the existing installations using these modules require a significant ground area, since each module has a limited maximum treatment capacity, and these installations therefore usually comprise numerous paralleled modules, linked at the water inlets and outlets by a complex set of pipes controlled by a set of valves and one or more control PLCs. The engineering and deployment of these installations are therefore very costly.